Commercial cooking of bacon has conventionally been performed in linear industrial microwave cooking systems that occupy substantial floor space in a food processing facility or other location and involve high energy costs. As the bacon is cooked, it shrinks and loses weight rapidly due primarily to the removal of fat. The bacon is cooked until it reaches a yield percentage determined by dividing the weight of the cooked bacon by the weight of the starting uncooked bacon. The desired yield percentage can be determined empirically for a particular oven, and must be low enough so that the bacon is thoroughly cooked and suitable for consumption.
Industrial microwave cooking ovens have a level of cooking nonuniformity which can be defined in terms of standard deviations. In one example, a particular type of bacon may be thoroughly cooked at a yield percentage of 40 or lower. In order to ensure that all of the bacon in the oven is thoroughly cooked, it may be desirable to set the yield percentage for the oven to a target percentage that is three standard deviations below the yield percentage of 40. If the oven has a standard deviation of 3%, then the target yield percentage for the oven would have to be set at 31 in order to ensure that substantially all of the bacon is cooked to a yield percentage of 40 or lower. At a target yield percentage of 31, approximately two-thirds of the bacon in the oven would be cooked to yield percentages between 28 and 34 (within one standard deviation). Approximately 95% of the bacon in the oven would be cooked to yield percentages between 25 and 37 (within two standard deviations of 31), and over 99% of the bacon would be cooked to yield percentages between 22 and 40 (within three standard deviations of 31). Essentially no bacon would be undercooked to a yield percentage greater than 40.
Another measure of cooking nonuniformity is the mean bandwidth variation. To determine the mean bandwidth variation, it is necessary to divide the cooking conveyor belt in to three sections of equal width. Then, determine the mean yield percentages for bacon strips placed and cooked in the first side portion, the center portion, and the second side portion of the belt. The mean bandwidth variation is the difference between the highest and the lowest of the three mean yield percentages. For example, if the first side portion has a mean yield percentage of 39.7, the center portion has a mean yield percentage of 33.7, and the second side portion has a mean yield percentage of 35.9, then the mean bandwidth variation will be 6.0% (the difference between 39.7 and 33.7). If the mean bandwidth variation is used as a control parameter, then the oven should be set so that the target yield percentage is no higher than the yield percentage required for fully cooked bacon minus the mean bandwidth variation.
Because of the wide variations in cooking experienced in industrial microwave processes, and the relatively high standard deviations and mean bandwidth variations, it has been necessary to set the target percentage for the oven far below the yield percentage needed for thoroughly cooked bacon, in order to ensure that all of the bacon is thoroughly cooked. There is a need or desire for an industrial bacon cooking process that has far greater uniformity and lower mean bandwidth variation so that the overall yield can be increased without undercooking any portion of the bacon. There is also a need or desire for an industrial bacon cooking process that occupies less floor space. There is also a need or desire for an industrial bacon cooking process that yields more uniformly cooked bacon.